Cover belt conveyors of this class are used, e.g., for continuously operating ship unloaders. However, they may be used for other purposes as well.
In vertical cover belt conveyors, the bulk material is clamped in the central area of the cover belt and the basic belt, thereby forming a continuous delivery strand. At least one of these belts is driven. If only one belt is driven, the other belt is carried by friction.
To make it possible to deliver varying delivery flows between zero and the maximum possible amount, the delivery cross section must be able to be varied within corresponding limits. This can be achieved by elastically mounting all support rollers or the support rollers of one of the two belts, especially those of the cover belt, or, as in the case of expanded foam belt conveyors, by the cover belt being elastically deformable and being able to penetrate to different depths in the sets of support rollers arranged in a trough-like manner.
Two short support rollers are integrated within a common bracket. Each bracket is mounted on a support structure by means of a prior-art rubber bearing (bearing with elastic rubber elements).
The rubber bearings must permit a certain angle of movement around the axis that is parallel to the delivery direction of the belt and a certain angle of movement around the axis that is parallel to the width of the belt. A sufficient center distance between the rubber bearing and the edge of the belt, on the one hand, and the surface of the edge area of the cover belt, on the other hand, shall be present as well. Furthermore, the edge of the support roller jacket adjacent to the rubber bearing must be located at a certain distance from the center of the rubber bearing in the direction of the center of the belt, and this edge of the support roller jacket shall be rounded in order to prevent the edge of the support roller from penetrating into the belt of the conveyor.
The strands of the basic and cover belts, which move together in the upward or downward direction and clamp the material being delivered between them, are compressed and guided by a plurality of support rollers arranged at closely spaced locations.